Summary details for Cheiracanthium pennyi O.P.-Cambridge, 1873

Distribution

The species has been recorded from the New Forest, Dorset and Surrey, and there is an old record from Wokingham, Berkshire, in 1872, when both sexes were found. Abundant on Chobham Common, Surrey, where it was first found in 1968 and has been recorded on many subsequent occasions. Possibly frequent on Whitmoor Common, but scarce elsewhere. It is fairly widespread in north-western and central Europe as far north as Sweden, where it is included on their Red List (Gärdenfors 2000). The species has not been recorded from Ireland.

Habitat and ecology

Lowland heathland. The spider occurs on mature dry heathland and is closely associated with the heather. Females, either with eggs or heavily gravid, have been found in cells on cross-leaved heath Erica tetralix, several dead flower heads having been drawn together and the cell made in their middle. On heather Calluna vulgaris, an immature female has been found in a cell, with the male waiting outside. Males have been found from June to August and females from May to August.

Status

Recorded from two hectads since 1992 where it still appears to be common. Despite a decline of 80% in hectads with spider records both before and after that date there is a strong possibility of under-recording.

Threats

Accidental fire or the too frequent use of fire as a management tool on the heathland habitat, and loss of habitat through changing land-use. A hundred hectares of Horton Common were ploughed up and turned over to agriculture in 1980. Birch and pine invasion is a threat on areas of heath, in the absence of burning, grazing or other active management. This is currently a problem in the spider's habitat on Chobham Common.

Management and conservation

Loss of heathland to birch and pine invasion should be prevented. Whilst fire is a valuable management tool for maintaining Calluna heath, it should be used at long enough intervals to allow the mature phase in the Calluna growth cycle to be reached and burning should be carried out on a rotation which allows this phase to be ever present on the site. If grazing is used in management, it may be necessary to fence off exclosures in which the Calluna can develop ungrazed for a number of years. Text based on Dawson, I.K., Harvey, P.R., Merrett, P. & Russell-Smith, A.R. (in prep.).